6 Aug
2016
6 Aug
'16
4:55 a.m.
"I've been restoring a HeathKit capacitor checker."
Which one, the IT-28? Those are really handy for finding leakage in
high-voltage caps, as they have a crazy-high (like 600V ?) power supply.
Unlike modern SS units, the IT-28 can test at practical working voltages.
There's data out there on how to finely calibrate those units, but I don't
see much point in it.. It's a lot of fiddly work and for what - to have the
best 40-year-old LCR meter? If you want a better than ballpark measure of L
or C, get one of the cheap uC-based swiss knife testers. A set of 1% metal
film resistors are cheap, though, and will improve stability.
If you ever feel the need to do semi-precision work with a device like the
IT-28, you're best off running it as a comparator and keeping a set of
precision value caps for reference. In that case, you only need to make
sure you have well matched resistor pairs in the bridge circuit.
On Fri, Aug 5, 2016 at 10:47 PM, dwight <dkelvey at hotmail.com> wrote:
I've been restoring a HeathKit capacitor checker.
I also have a couple HP counters with Nixies.
I even have a 10 channel printer ( need to repair the
roller ). I've found that one doesn't need the expensive
ink roller ( though I'd love to have one, used or not ).
I use the two layer impact paper.
Dwight
________________________________
From: cctalk <cctalk-bounces at classiccmp.org> on behalf of Ian S. King <
isking at uw.edu>
Sent: Sunday, July 31, 2016 3:46:13 PM
To: General Discussion: On-Topic and Off-Topic Posts
Subject: Re: the value of old test and repair equipment
I really like my old test gear and yes, it just seems right to be restoring
vintage computers with vintage instruments. HP scopes, logic analyzers,
DVMs; function generator; Tek scope, frequency counter; as well as just
'sundry'. But I did break down and buy a DDS frequency generator to work
on my VHF/UHF ham gear.
On Sat, Jul 30, 2016 at 6:07 PM, drlegendre . <drlegendre at gmail.com>
wrote:
--
Ian S. King, MSIS, MSCS, Ph.D. Candidate
The Information School <http://ischool.uw.edu>
Dissertation: "Why the Conversation Mattered: Constructing a Sociotechnical
Narrative Through a Design Lens
Archivist, Voices From the Rwanda Tribunal <http://tribunalvoices.org>
Value Sensitive Design Research Lab <http://vsdesign.org>
University of Washington
There is an old Vulcan saying: "Only Nixon could go to China."
In fact, the value of old test gear varies
tremendously..
Vacuum tube testers of certain makes & models are near the top of the
food
chain, with clean, working examples pulling
$1500+ (USD) on a very
regular
basis.
There's also a strong following for much 'classic' audio analysis gear
(HD
meters, ID meters, spectrum analyzers, etc.) some
very fine multi-meters
and anything really hi-end like General Radio, Breull & Kejjr, HP, and so
forth.
Some very early examples from the 1910s to 30's also pull good value
simply
for visual appeal. Much of this gear is
resplendent with embossed,
enameled
panels, sculpted Bakelite knobs, large meter
movements and an overall Art
Deco styling.
Seen a nice Supreme Diagnometer recently? Or any of the 40s-70s era
English
made tube testers, like the AVO? Hickok also made
a series of bench VTVMs
with massive chromed meters, designed to be large enough that they can be
read from many feet away.. those are beautiful for display, and guess
what
- they work great, too!
On Thu, Jul 28, 2016 at 5:24 PM, Dale H. Cook <radiotest at juno.com>
wrote:
At 03:52 PM 7/28/2016, Electronics Plus wrote:
>... does as-is old test and repair equip that won't be particularly
cheap
have interest to you guys?
It depends entirely on the make and model of equipment. I always have a
laundry list of stuff I am looking for - one of the reasons why I bring
my
tablet to meets.
Dale H. Cook, GR / HP Collector, Roanoke/Lynchburg, VA
http://plymouthcolony.net/starcity/radios/index.html